LONDON (REUTERS) - British Prime Minister Theresa May appointed Gavin Williamson as new defence minister on Thursday (Nov 2), replacing Michael Fallon who resigned amid a growing sexual harassment scandal that prompted calls for a wholesale change in the "locker room" culture in parliament..

"The Queen has been pleased to approve the appointment of Rt Hon Gavin Williamson as Secretary of State for Defence," May's spokesman said.

Williamson was the chief whip of May's Conservative Party.

The loss of Fallon, described by Conservative sources as a political "Rottweiler", leaves May with a hole in her Cabinet, already at odds on everything from Britain's departure from the European Union to the government's austerity agenda.

In his letter of resignation to May, Fallon, who had apologised earlier this week for repeatedly touching a radio presenter's knee in 2002, said there had been many allegations about lawmakers, including "some about my previous conduct".

"Many of these have been false but I accept that in the past I have fallen below the high standards that we require of the armed forces that I have the honour to represent," he said, offering no detail on the nature of any other allegations.

"I have reflected on my position and I am therefore resigning as defence secretary."

May replied in a letter saying she appreciated "the characteristically serious manner" in which

Fallon had considered his position and "the particular example you wish to set to servicemen and women and others".

This story is developing.